Hot journal alarm apparatus



T 1 2%, 1947. e. K. NEWELL 2,420,969

HOT JOURNAL ALARM APPARATUS Filed June 9, 1944 Gar/4A I 69 2/ I [5d 2022 ll Ic 3a I 2/ I9 .22 6

Locomotive I70 9/ INVENTOR. Gen ZLNeweZZ Patented May 20, 1947 HOTJOURNAL ALARM APPARATUS George K. Newell, near Pitcairn, Pa., assignorto The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation ofPennsylvania Application June 9, 1944, Serial No. 539,468

.2 Claims. (01. 177-311) This. invention relates to hot journal alarmapparatus, that is, apparatus for giving a signal or an alarm whenever abearing or journal approaches an abnormally hot temperature condition,and has particular relation to hot journal alarm apparatus for railwaycars and trains.

Railroads have long sought a simple and inexpensive apparatus forapprising the engineer or other member of a train crew of the occurrenceof a hot-box" or abnormally high heat,

condition in the axle journal on any of the cars of the train, becausehot-boxes not only damage the parts of the journals but may even resultin breakage of an axle and possible wreckage of a train due toderailment of a car following breakage of the axle. I

Various devices and apparatus have been proposed for the purpose ofsignaling the occurrence of a hot-box on railway cars and trains. Forexample, in my copending application, Serial No. 528,710, filed March30, 1944, and assigned to the assignee of this application, I havedisclosed a hot journal alarm apparatus employing for each individualaxle journal a. Wheatstone bridge arrangement of resistors, two of theresistors of the bridge circuit being exposed tothe heat in the axlejournal and the. remaining two of the resistors being exposed to anexternal or ambient temperature as, for example, that in the car body. Arelay is connected in such a, manner as to be responsiv to theunbalanced voltage created in the Wheatstone bridge circuit by reason ofan abnormal increase in the resistance of the two resistors locatedwithin the axle journal due to an abnormal rise of temperature in thejournal. Visual and audible signal devices both on the individual carand on the locomotive are actuated in response to the operation of therelay.

It is an object of my present invention to provide a, hot journal alarmsystem of the Wheatstone bridge type disclosed in my copendingapplication, Serial No. 528,710, and further characterized by animproved arrangement which simplifies the construction and reduces thecost thereof.

More specifically, it is an object of my present invention to provide ahot journal alarm apparatus of the Wheatstone bridge type wherein anindication of an abnormal heat condition in an axle journal is obtainedon the basis of the creation of at least a certain predeterminedunbalanced voltage condition in the Wheatstone bridge for successivelyassociating such master resistance cartridge with each of a plurality ofresistance cartridges associated directly with a plurality ofcorresponding axle journals.

It is a further object of my present invention to provide hot journalalarm apparatus of the type-indicated in the foregoing objects andfurther characterized by a rotary selector switch for successivelyassociating the master resistance cartridge with each of a plurality ofaxle associated resistance cartridges.

The above objects, and other objects of my invention which will beapparent hereinafter, are attained by means of apparatus subsequently tobe described andldisclosed in the diagrammatic plan view constitutingthe single 'figure of the accompanying drawing.

Description Referring to the single figure of the drawing, the alarmapparatus of the hot journal alarm apparatus disclosed therein isindicated as applied to a locomotive and two cars, designated car A andcar "3 respectively. The apparatus for car B duplicates that shown forcar A and is accordingly omitted, for simplicity, from the drawing. Theapparatus for car A includes a plurality of resistance cartridges Ila,lib, llc, Ild, He, II Hg, and it, each associated with a correspondingjournal box or casing of two four-wheel trucks located at opposite endsof the car.

The apparatus also includes a master resistance cartridge l2; a rotaryselector switch l3 effective to successively associate the masterresistance cartridge I2 with the journal-associated cartridges Ila tollh, respectively, in a Wheatstone bridge arrangement hereinafter to bemore fully described; and a suitable motor l4, illustrated as of theelectric type, for operating the rotary selector switch I3.

The apparatus further includes a two-winding relay ill of the manuallyreset type which serves to control the circuit of signal devices in theform of an alarm bell or buzzer I6 and a signal lamp I! on the car, andan alarm bell l6a and a signal poses of the present application, it isdeemed sufflcient therefore to point out that each resistance cartridge||a to Hit comprises a support in the form of a screw plug I8 and tworesistors or reslstance elements I9 and 28, respectively, each of whichmay be in the form of a, coil and disposed respectively on twoconcentrically supported insulating sleeve elements (not shown) attachedto the plug 8. The plug 8 of each of the resistance cartridges isscrewed into the outer threaded end of a bore or heat well 2| providedin a suitable location in the metallic portion of the correspondingjournal box or casing 22 in such a manner as to expose the resistors l9and 28 to the heat condition in the journal.

The master resistance cartridge I2 is similar in construction to thejournal-associated resistance cartridges but differs therefromessentially in that it is provided with a support l8a, corresponding tothe screw plug l8, and a sleeve type perforated housing 23 attached, asby a screw connection, to the support l8 a in such a manner as toenclose the resistance elements 24 and 25 of the master resistancecartridge. The resistance elements 24 and 25 of the master resistancecartridge |2 may be in coil form and carried respectively oncorresponding tubular insulating elements disposed in concentricrelation and suitably attached to the support |8a in the manner fullydisclosed and described in my copending application, Serial No. 528,710.

The rotary selector switch l3, as diagrammatieally shown, may comprisetwo concentrically arranged contact rings disposed in a common plane,the inner ring having two substantially semicircular contact segments 25and 21 separated at the ends thereof by a pair of short insulatingsegments 28. The outer ring comprises a series of short contactsegments, illustrated as sixteen in number and designated 3|, 32, 33,34, 35, 36, 31, 38, 4|, 42, 43, 44, 45, 45, 41, and 48 in successionaround the periphery of the ring. Suitable insulating segments 29 areinterposed between successive contacts 3| etc. to 48 respectively, whichinsulating segments are preferably flush with the contact face of thecontact segments.

The rotary selector switch |3 further includes a rotary shaft 58 and aninsulating member 5| fixed thereon. At each of the diametrically ppositeends of the member is secured a metallic contact bridging element 53 and54, respectively. The contact bridging elements 53 and 54 are resilientand flexible and are so disposed as to firmly engage and bridge theconcentric contact rings at diametrically opposite pointssimultaneously.

The shaft 58 is suitably connected to and driven by the rotary elementof the motor l4, as indicated by the broken line 55. The motor |4 may beof any suitable type, but I prefer to employ a motor of the periodicallyenergized type, similar in principle to electric clocks of theperiodically energized type, so that the motor l4 may be drivencontinuously with a minimum drain of energy from the battery 55 locatedon the car. In the case of passenger cars, the battery 58 may be theusual car lighting battery adapted to be maintainedcharged by anaxle-driven generator provideo on the car.

The circuit for supplying energy from the battery 56 to the motor l4will be readily apparent from the drawing. One terminal of the motor isconnected to the negative or grounded terminal of the battery 56, asthrough a ground connection in the manner shown, and the other terminalof the motor I4 is connected by a wire 51 to a so-called positivebattery wire 58 that is, in turn,

connected by a suitable switch 59 (illustrated as a knife switch) to thepositive terminal-of the battery 56.

One terminal of each of the resistors or resistance element IQ of all ofthe Journal-associated resistance cartridges Ila to Hit is connected tothe positive battery wire 58 and the opposite terminal in each case, isconnected by a corresponding Wire 8|, 62, 53, 64, 55, 86, 61 and 88respectively to the contact segments 3| to 38, respectively, in theouter ring of the rotary selector switch l3.

One terminal of each of the resistors 28 of the I journal-associatedcartridges Ila to llh is connected to the associated support or screwplug l8 and thus, by reason of the contact of the plug with the groundedjcumal casing 22, to the negative terminal of the battery 56. The otherterminal of each of the resistors 28 is connected by a correspondingwire ll, l2, l3, l4, I5, 15, I1 and 18, respectively, to the contactsegments 4| to 48, respectively, in the outer ring of the selectorswitch l3.

One terminal of the resistor 24 of the master resistance cartridge |2 isconnected by a wire 19 to the positive battery wire 58 and the otherterminal is connected by a wire 88 to the contact segment 21 of theinner contact ring of selector switch l3 in such a manner as to notinterfere with the movement of the contact bridging elements 53 and 54and the engagement thereof with the contact segments in the concentricrings.

One terminal of the resistor 25 of the master resistance cartridge i2 isconnected to the support |8a which is, in turn, connected through aground connection to the negative terminal of the battery 56, in themanner shown. The other terminal of resistor 25 is connected by a wire8| to the contact segment 26 of the inner contact ring of the selectorswitch l3 in such a manner as not to interfere with the movement of thecontact bridging elements 53 and 54 and the engagement thereof with thecontact segments of the concentric rings.

The disposition of the contact bridging elements 53 and 54 of the rotaryselector switch I3 is such that when the contact bridging element 53connects the contact segment 3| in the outer ring to the contact segment25 in the inner ring, the contact bridging element 54 simultaneouslyconnects the contact segment 4| in the outer ring to the contact segment21 in the inner ring. A Wheatstone bridge circuit is thus established,associating the resistance elements I!) and 28 of the journal-associatedresistance cartridge ||a with the resistance elements 24 and 25 of themaster resistance cartridge l2. This circuit may be traced from thepositive terminal of the battery 55 by way of the switch 59 to bus wire58 where the circuit divides into two parallel branches, one branchextending by way of the resistor l9, wire 6|, contact element 3|,contact bridging element 53, contact segment 26, wire 8|, resistor 25 ofthe master resistance cartridge l2, and to the negative terminal of thebattery 55 through the ground connection shown. The other branch of thecircuit extends by way of the wire 19, resistor 24 of the masterresistance cartridge i2, wire 80, contact segment 21, contact bridgingelement 54, contact element 4|, wire 7|, resistor 28 of resistancecartridge Ila, and thence to the negative or grounded terminal of thebattery 56.

In a similar manner, while the contact bridging element 58 connects thecontact segment 32 to the contact segment 28 of the selector switch I3,the contact bridging element 58 simultaneously connects the contactsegment 82 to the contact segment 21. Upon analysis and tracing of thecircuits in the manner previously indicated, it will be seen that theresistors l8 and 28 of the resistance cartridge lib are therebyassociated in a Wheatstone bridge circuit with the resistors 24 and ofthe master resistance cartridge l2.

It may be demonstrated, similarly, that for each position of the rotor-5l of the rotary selector switch l3 in which the contact bridgingelement 53 respectively engages the contact segments 33, 34, 35, 36, 31,and 38, the resistors l9 and 28 of the resistance cartridges Ilc, Ild,lle, Hf, Hg and Hit are successively associated in a Wheatstone bridgecircuit with the resistors 24 and 25 of the master resistance cartridgel2.

It will be understood that the motor it rotates the rotary member 5| ofthe selector switch l3, continuously, as long as the switch 59 is inclosed position; and that the voltage of the battery 53 is likewiseimposed on each successive Wheatstone bridge circuit as long as theswitch 59 is closed. Opening of the switch 58 stops the motor l4 andprevents drain of current from the battery 56 regardless of the stoppedposition of the contact bridging elements 53 and 54 of the selectorswitch l3.

The speed at which the shaft 58 and rotary member 5| of the selectorswitch i3 is driven by the motor I4 may vary as desired. For example,the speed of the rotary member 5! may be one revolution every twominutes.

Any unbalanced voltage that may exist in each Wheatstone bridge circuit,as it is set up by the selector switch I3, is present across the wires80 and BI. A so-called pick-u winding |5a of the relay i5 that isconnected across wires and 8| is thus energized by a current varyingproportionately to the unbalanced voltage on the circuit. The resistorsl9 and 28 of the journalassociated resistance cartridges and theresistors 24 and 25 of the master resistance cartridge l2 are sodesigned with respect to the relative resistance thereof and to thevoltage of the battery 56 that the pick-up winding l5a is notsuihciently energized to cause pick-up, that is actuation to closedposition, of the front contacts 150 and l5d of the relay l5 unless anabnormally high heat or "hot-box condition exists in any of the axlejournals at the time the Wheatstone bridge circuit including thecorresponding journal-associated resistance cartridge is set up.

The relay l5 has a second winding i5b that functions as a. stick orholding winding for the purpose of maintaining the contacts of the relayin their picked-up or closed position once they are actuated thereto inresponse to suflicient energization of the pick-up winding l5a. Thecircuit of the holding winding 15b may be readily traced from thepositive battery wire 58 by way of the branch wire 19, a wire '85, afront contact I of relay l5, holding winding 15b of the relay t5 andthence to the negative terminal of the battery 56 as through a groundedconnection in the manner shown.

The front contact l5d of relay I5 is effective in its picked-up orclosed position to establish a circuit for energizing the signal devicesIt and I! on car A as well as signal devices 18a and Ila on thelocomotive.

The circuit for the signal devices It and I1 18a and Ma on thelocomotive may be traced from the positive battery wire 58 to the wire88 as Just described, thence by way of an asymmetric device or rectifier8'8, which may be of the dry disk or tube type, included in the wire 88.to a train wire 88 which comprises sections on the several cars andlocomotive connected through suitable flexible couplings 88. The signaldevices 18a and Ila on the locomotive are connected in parallel relationbetween a branch wire 8! of the train wire 88 on the locomotive and thenegative terminal of the battery 58 as through aground I connection inthe manner shown.

It will thus be apparent that when the relay I5 is Picked-up, the signaldevices It and i1 onthe corresponding car and the signal devices Iliaand Ila on the locomotive are simultaneously operated and continue to beoperated until the relay i5 is manually restored to its dropped-outposition by means of the operating button or handle 92. The relay l5 mayalso be restored to its dropped-out position by opening the batterycontrol switch 59, thereby interrupting energization of the holdingwinding 15b of the relay 15.

It is the intention of the arrangement disclosed to necessitate apositive acknowledgement by some member of the train crew in response tothe operation of the signal devices on the car or cars and on thelocomotive in order to terminate their operation. The likelihood that ahot journal or hot-box condition will he accidentally or negligentlydisregarded is thus substantially eliminated, for the train crew willnot disregard their imposed duty of acknowledging the signal.

It should be apparent that, by reason of the provision of the asymmetricdevice 81 on each of the cars, the occurrence of a hot-box or hotjournal on one car and the consequent actuation of thesignal devices l6and i! thereon will be inefiective to cause actuation of thecorresponding signal devices on another car but will, at the same time,be efi'ective to cause energization of. the signal devices on thelocomotive. This arrangement, it will be understood, is not a part of mypresent invention, being heretofore disclosed and claimed in my priorcopending application Serial No. 528,709, filed March 30, 1944, andassigned to the assignee of the present application.

Summarizing, it will be seen that I have disclosed herein a novel hotjournal alarm apparatus including a plurality of resistance cartridgesassociated respectively with difierent axle journals on a car, aso-called master resistance cartridge exposed to ambient temperaturewithin a car, and a continuously operated rotary selector switch forsuccessively and periodically connecting each of the joumal-associatedresistance cartridges to the master resistance cartridge in a Wheatstonebridge circuit arrangement whereby the unbalanced voltage that may becreated in each successively established Wheatstone bridge vices to,continue in operation, once actuated in response to an abnormal heatcondition in a Journal on a car, until the signal is acknowledged bysome positive act on the part of some member of the train crew.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

1. Apparatusfor signaling the heat condition in any one of a pluralityof zones, said apparatus comprising a plurality of resistance units eachor which is disposed individually in a corresponding different one ofsaid zones and each unit having two resistance elements unii'ormlyailected by variations of temperature in the corresponding zone. asingle additional resistance unit disposed additional unit having tworesistance elements in a certain diil'erent zone not subject to thetemperature variations occurring in said plurality of zones, saidadditional resistance unit having two resistance elements uniformlyafiected by variations oi'temperature in the said certain differentzone, a source of direct current voltage, a rotary selector switchdevice operative tovprogressively and periodically connect one or theresistance elements of each of said plurality oi resistance units inseries relation with one or the resistance elements of said additionalresistance unit across said source of voltage and, simultaneously, alsoconnect the other resistance element of the same one oi said pluralityof resistance units inseries relation with the other resistance elementof said additional resistance unit across said source of voltage, saidresistance elements being further so disposed that each constitutes onearm of a Wheatstone bridge arrangement and that the simultaneous anduniform variation of resistance of both of the resistance elements oi!any one of said plurality of resistance units produces an unbalancedvoltage condition of the bridge arrangement, and electroresponsive meansoperatively responsive to a predetermined unbalanced voltage produced onthe Wheatstone bridge arrangement.

vidually disposed in a corresponding different one of said zones andincludes two resistance elements uniformly afi'ected by variations ortemperature in the corresponding zone, an additional unit disposed in acertain diilerent zone subject only to variations of ambienttemperature, said both uniformly affected by the temperature conditionin said certain diflerent zone, a source oi direct current voltage, arotary selector switch device including a rotary contact mechanism, saidrotary selector switch device being operative when the rotary contactmechanism rotates continuously in one direction to cause one oi theresistance elements 01 said certain unit to be connected across saidvoltage source in-series relation with one or the resistance elements ofeach one or said plurality of units progressively and repeatedly andalso to simultaneously cause the other of said resistance elements-oi!said additional unit to be connected across said voltage source inseries relation with the remaining resistance element 01' each of saidplurality of units progressively and repeatedly whereby to cause aplurality of Wheatstone bridge arrangements to be progressively andrepeatedly established in each of which the two resistance elements ofthe saidadditional unit are always included, the connections establishedby said rotary selector switch device being such that the simultaneousand uniform variation of resistance 01' bothof the resistance elementsor any one of said plurality of units functions to produce an unbalancedvoltage condition of the corresponding bridge arrangement substantiallyin accordance with the degree of variation of the temperature in thecorresponding zone with respect to the temperature in said certaindifierent zone, and electroresponsive means operatively responsive onlyto an unbalarmed voltage exceeding a certain value produced on anyone ofsaid Wheatstone bridge arrangements.

GEORGE K. NEWEIL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED s'rA'rEs PATENTS

